The overall objective of research at the Buck Institute for Research on Aging is to understand mechanisms of aging and its associated diseases in order to extend the healthy years of human life. Research at the Buck Institute is reaching the stage at which techniques perfected for isolated cells can now be applied to more complex multicellular organisms. This shared instrumentation proposal seeks funds for the purchase of a Complex Object Parametric Analyzer and Sorter (COPAS(tm)) FP PRO flow cytometer. This instrument will be housed and maintained at the Buck Institute's Morphology & Imaging Core and will be used by 10 independent principal investigators from the Buck Institute and 3 external investigators from the University of California, San Francisco. Together, these researchers bring together 16 NIH-funded grants, all of which will benefit from the ability to analyze and sort large particles. The unique capability of the COPAS to sort objects that are too large or too fragile for conventional flow cytometry allows analysis and sorting of whole multicellular organisms, intact cell clusters, and large mammalian cells. The data obtained from the requested instrument will be critical to understand various disease models and paradigms. Indeed, these research projects encompass the study of neurodegenerative diseases processes, the regenerative capacity of stem cells, the identification of novel protein targets or biomarkers for obesity, and the identification of compounds that modulate mitochondrial dysfunction and proteostasis in aging and age-related diseases. These projects are unified in using molecular, genetic, and biochemical techniques to ask how specific gene products influence cellular and organismal aging processes. The majority of these projects are not possible without the use of this instrument. Overall, the acquisition of the COPAS FP PRO flow cytometer will greatly improve the throughput and experimental design of projects that target important aspects of human health and healthspan.